Drum

ABSTRACT

An adjustable pitch musical drum is provided which includes a tubular cylindrical casing having its axis vertical, and a conventional drum head in tension over another end of the casing. A plurality of legs support the casing off the floor and a foot pedal is provided below the casing for adjusting the tension in the drum head. A tensioning mechanism connects the pedal to the drum head so that a relatively large movement of the pedal results in a small tensioning movement at the drum head to vary the frequency and hence the pitch of the note produced by the drum.

United States Patent Bemben A3,685,389 1451 Aug. 2z, 1972 FOREIGNPATENTS 4OR APPLICATIONS [541 DRUM [72] Inventor: Fr Il. Tl omBembenMoom 1,095,169 12/1967 GreatBritain............L..4/4ll stone,Ontario, Canada Primary Examiner-Richard B. Wilkinson AssistantExamner-Lawrence R. Franklin [22] Filed:

Attorney-Rogers, Bereskin & Parr Aug. 20, 1970 [21] Appl. No.: 65,441ABSTRACT An adjustable pitch musical drum is provided whichV includes atubular cylindrical casing having its axis (gl. sullds/g vertical, and aconventional drum head in tension over another end of the casing Aplurality of legs Support [58]. Field of Search..............84/41l,411.1, 413, 419 the casing OH the floor and a foot pedal is providednsion in the drum head. A tensioning mechanism connects the pedal tobelow the casing for adjusting the te [56] References Cited the drumhead so that a relatively large movement of UNITED STATES PATENTS thepedal results in a small tensioning movement at the drum head to varythe frequency and hence the 2,259,268 10/194lROblSQnm..........,........,84/4l9 pitch ofthe note produced by thedrum. 2,261,119 11/1941 Ludwig et al................84/419 2,548,2714/1951 Percy...........................84/411 2Clains, 4Drawing FiguresPATENT'ED/uszz |912 3,685,389

snm 1 nr 2 FRANKLIN THEODORE BEMBEN PTENTDAuszz |912 SHEET 2 0F 2 FIG. 3

' INVENTOR. FRA-NKUN THEODORE BEMBEn DRUM This invention relates to amusical drum of a type which can be adjusted continuously to vary thefrequency of vibration at the drum head to give a range of musicalpitch. i

A drummer in a dance band, or in a group playing popular music, is oftenrequired to play a solo or to play a piece of music with a minimum ofaccompaniment. With the exception of the expensive and cumbersometimpani, drums are adjusted to a predetermined tension at the head orskin of the drum and the drum remains in this condition while it isbeing played. The frequency of vibration of the drum head is controlledby the fixed tension in the drum head. However, the drum can be made tomake different sounds by hitting it with a variety of blows of differentstrength. Commonly this is said to change the pitch. For the purposes ofthe present description however, the word pitch is used to describeresults obtained by varying the tension in the drum head rather thanchanges in the loudness of the note. For a given drum, although theloudness can be varied, the frequency of vibration (and hence the pitch)is fixed for a given head tension.

Commonly a drummer uses a number of different drums to obtain differenteffects and different notes. It is an object of the present invention toprovide a variable pitch drum which a drummer can use to obtain neweffects and which may be used in place of one of the drums presentlyused by a drummer.

Accordingly, in a particular preferred embodiment of the invention, anadjustable pitch drum is provided which includes a tubular cylindricalcasing having its axis vertical, and a conventional drum head in tensionover an upper end of the casing. A plurality of legs support the casingoff the floor and a foot pedal is provided below the casing foradjusting the tension in the drum head. A vtensioning mechanism connectsthe pedal to the drum head so that a relatively large movement at thepedal results in a small tensioning movement at the drum head to varythe frequency and hence the pitch of the note produced by the drum.

The invention will be better understood with reference to the drawings,wherein:

FIG. 1 is a partially sectioned perspective view of a drum according tothe invention;

FIG. 2 is a side sectional view on lines 2-2 of FIG. l;

FIG. 3 is a side sectional view on lines 3-3 of FIG. 1; and

FIG. 4 is a side sectional view on lines 4-4 of FIG. 1.

Reference is first made to FIG. l which shows a drum having a tubularcylindrical casing or shell 12 and a drum head 14. Three generallyupright legs 16 support the casing 12 and a foot pedal assembly 18 ispivotally attached by screws 20 to a framework 22 which is in turnattached to the casing 12. Movement of the foot pedal assembly 18results in moving a tensioning mechanism 24 having a relatively largemechanical advantage for tensioning the drum head 14. The mechanism 24is arranged so that a relatively large movement of the foot pedalassembly 18 results in a small tensioning movement at the drum head withrelatively small variations in the force required at the foot pedalassembly.

The casing 12 has a rounded upper side 26 for receiving the head 14 suchthat the head can be stretched radially over the rounded side 26 withoutdamage to the head. Head 14 consists of a generally circular skin 28attached at its periphery to a hoop 30 which is adapted to pass over theupper end of the casing 12. An annular rim 32 is pulled downwardly onthe hoop 30 by eight axial bolts 34 to tension the skin 28. Each of thebolts 34 is threadably engaged in a cylindrical slider 35 which is freeto slide axially in a housing 36 in response to movements of the pedalassembly 18. As the pedal assembly 18 is depressed, the sliders 35 andbolts 34 move downwardly and increase the tension in the skin 28 toincrease the pitch of the note produced when the skin 28 is struck. Oncethe pedal assembly is released, the skin tension draws the mechanism 24and pedal assembly 18 back to its original position corresponding to thelowest pitch in the drums musical range.

The legs 16 are adjustably mounted in leg supports 38 on the casing 12for axial movement to adjust the height of the drum. Locking screws 40are threadably engaged in respective leg supports 38 to lock the legs inplace.

The framework 22 consists of a first member 42 which extendsdiametrically across the lower open end of the drum 10, and is attachedto the casing l2 by integral upright portions 44 and fasteners 46 whichpass through the upright portions 44 and through the casing l2. A secondmember 48 is welded to the member 42 and extends horizontally from thecenter of the first member 42 terminating in a further upright portion50 which is attached by fasteners 52 to g e casing l2. A journal bearing54 is attached to an upaer side of the first member 42 with the axis ofthe bearing coincident with the axis of the casing 12. The bearingslidably receives a lower push rod 56 which is part of the mechanism 24and which has an enlarged lower end 58 for transmitting motion from thefoot pedal assembly 18 to the tensioning mechanism 24.

The lower push rod 56 has an upper threaded portion 60 which projectsthrough an opening in a lower pivot block 62. A pair of nuts 64 (one ofwhich is shown) are threadably engaged on the upper portion 60, oneabove and one below the pivot block 62 to locate the pivot block on thelower push rod 56. A third nut 64 is also engaged on the portion 60 andserves as a stop for liniting downward movement of the push rod byengaging an upper surface of the journal bearing 54. Three lower momentarms 66 are mounted in the block 62 such that the arms are free to pivotand slide in the block 62. The arms 66 are spaced equally about block 62and extend generally radially from the block 62 and are pivotallyconnected at their distal or outer ends by pins 68 to pivot supportplates 7u. Each of the plates 70 is connected by bolts 72 which projectthrough the casing 12 and are threadably engaged in a corresponding legsupport 38. The arms 66 are connected to a respec one of three curvedintermediate moment arms 74 .'xiiich extend downwardly and radially froma coupling plate 76. Each intermediate arm terminates at a forked end 78which is pivotally attached by pins 80 to a corresponding arm 66adjacent an outer end of the arm 66. Each of the moment arms 74 isshaped so that at its lower end, the fork 78 is substantially at rightangles to the axis of an associated radial arm 66 and the upper endextends axially through the coupling plate 76. This threaded and hastwognuts 80 (one'fofwhichfis shown) arranged one above and onebelowthef'plat'e 76^1tozat tach the arm to the plate. Y

. The plate 76 also has a central opening forr-ecieiving a threadedlupper push rod 82 which has two-nuts 83 (one of which is shown) engagedone above1and l'one below the plate 76 for locking the upper push rod82-to the plate 76. Upper push rod 82 is threadablyengaged in an upperpivot block8 4 and threaded'intoth'e'block as will be explained; Eightequally spaced upper-moment arms 88 are mounted at their inner'ends`in=the block 84 such that the arms 88 are free tofpivot' in `'avertical plane and to slide radially in block 84;:"I`he arms 88 extendradially from the block '841 a'nditheir respective outer ends engage incorresponding cylindrical sliders 35. Reference is next made to FIG. 2which showsja moment arm 88 engaged in a cylindrical slider 35 which isfree to move axially in the housingf36. The'arra'ngement shown in FIG. 2is typical of all *eight of the couplings between each of the rods 88and afcorresponding bolt 34. The rim 32 consists of a generallycylindrical portion 92 which is ilaredfoutwardlyatit's upper end 94 toextend above the skin 28; The upper end 94 is used for what is commonlycalled 'a rim shot. (This is when the drummer hits the skin 28``andupper portiong94 of rim 32 simultaneously to obtairia distinctivenoise). A radially extending flange portion 96 extends outwardly fromthe low'er end of the portion 92 and has openings 98 for receiving eightbolts"34. The rim terminates in a lip which vextends downwardly from theouter edge of the portionff96to rigidify the rim 32. The underside ofthe radialportion 96 engages the hoop 30 of the head 14 so that the skin28 is stretched when bolts 34 are tightened; lBolt34 is threadablyengaged in the cylindrical slider 35 and the slider 35 isreciprocallyengaged in an upperopening 102 in the housing 36 and in asmaller clearance hole 104 at the bottom of the housing36; Bolts106arelehgaged through a pivot plate 108-and projectlthro'u'gh thecasing 12 to threadablyfengage in the housing36s'o that the bolts attachboth the plate v108 andth'e housing 36 to the casing 12. f @i ai Theupper radial arm 88 projects through an oversize opening 110 inthe`plate 108 and is prevented from moving inwardly through the opening 110by av collar 112 attached to ,the armv 88. The outer end 114 ofithe arm.A88 is ofgreduced diameter and engages inl'a'contoured and slottedrecess 116 which permits limited ana gular motion ofthe arm 88 `relativeto the cylindrical' completing the .descriptionof the operation of theteni* Reference` is next made ,toFlG. 3 which shows'the 6,5.'

sioning mechanism 24 (FIG. 1 x

lowerpivotV block 62 and one of the lower moment arms 66 engaged .inoneof three openings 118 `in they block 62. Each of theopenings is similarin shape to opening 116 (FIG. 2) to permit the arm 66 to move an-*glaily`-ina"vertical plane with respect to the pivot 'blocl62 andto'slide radially'as the block 62 moves axially'.` lTheirblock62' can beof any suitable metallic material or a rigid plastic. Also, if preferreda dense composition can be used, and this has the advantage thfatittends'to damp undesirablevibrations in the' teh'sioning'mechanism 24.

""FIGi-4 illustrates the `upper pivot block 84 which has eightopnngs' 120 which are also similar in shape to "openings 1'16"(FIG. 2) in theslider 35. However, the rbl'tick84is'made of respective upper and lowerhalves 1241", 123 to facilitate assembly. The upper push rod 82isthradablyengag'ed in the lower half 123 and locked in plticeby a nut125. A bolt 86 extends through upper Thalffl21j'and ythreadably engagesin lower half 123 to 'hld "the "halves `in engagement. Each opening 120'receives a corresponding inner end 122 of an upper moment 88 to permitthe end 122 to pivot in a verticalplaneaiid to move radially as thepivot block 84 moves axially. The inner end 122 is of reduced diametert`linit lthesize of openings and hence to limit the size of the block84. The block 84' is of similar material to the block 62 or any othersuitable material e used.

, eturning now to FIG. 1, the pedal assembly 18 consflis'ts'of abell-crank lever 124 having an inner end 126 'tV engage in a slot 128 inthe enlarged lower end 58 of the..push rod 56. The bell-crank lever 124is free to ftatej about a fitted bolt. 129 in a U-shaped bracket4131.atvtachedby screws 20fto member 48, and has a hiny'ge130 attachedto its outer end 132. The hinge 130 also attached to an upper end of afirst member 134 adjustable link 136. A second member 138 is releasablyconnected by screws 140 to the first member 134:;and has a `plurality ofholes 142 to permit the screws--ftolbe repositioned to adjust the lengthof the lin124136,.Av second hinge 144 is attached to the lower end ofthesecond member 138 and to the upper end of an inclined foot plate 146.The foot plate 146 terminatesaat its" lower end in a pivotal connectionto a base plate 148 which normally rests on the floor. l

'In operation, 4when a drummer places his foot on the inclined footplate 146 with his heel on the base plate 148 hecanpivot the plate 146about the baseplate 148 t0 rotate the-bellcrank lever 124 about thepivot bolt 129. This results in an upward force on the lower pushrod'56to1slide'the rod 56 upwardly through vthe journal bearingA54.f\.l."his upward motion of the rod 56 andconsequentlybl''thepivotblock 62 rotates the 4`vlower mo mentgarmslfabout pivot pins 68 insupport plates 70. Because Ltheintermediate moment arm 74 is connectedtot thellower moment arm 66 adjacent the pivot pins 68,thereis'aimechanical advantage created such that the upwar'drforcein',thelarms 74 is greater than the upward frceinthe push-'rod 56. i

fFrther mechanical advantage is obtained when the plate76 and pivotblock 84 are moved upwardly by the force Linfth'elnioment arms 74. Thepivot block transfers th:force' tother u'pper moment arms 88 which arepivoted adjace'nttheir outer ends in pivot plates 108to draw thecylindrical sliders 35 downwardly'. There is a relativelylargefrnechanical advantage in the moment arms- 88 so that lthiscombined with the mechanicaldvantage in the other parts of the mechanism24 results in a very small downward movement of the rim 32 for acorresponding large movement of the inclined foot plate 146.Consequently the drummer is able to tension the skin 28 of the drum head14 with relatively little effort.

One of the features of the adjustable drum is that the moment arms 66,and 88 are inclined downwardly from the horizontal with the drum in theposition shown in FIG. l by a predetermined angle such that when thefoot plate is fully depressed, the arms 66 and 88 are inclined upwardlyfrom the horizontal by the same predetermined angle. This eliminates theneed for expensive pivotal connections at the cylindrical slider 35, andpivot blocks 62 and 84 and gives a substantially constant mechanicaladvantage for all positions of the foot plate 146.

The pedal assembly 18 can be removed from the drum for transporting thedrum by removing the screws 20. Also the legs 16 can be removed fromsupports 38 by first loosening screws 40 and sliding legs 16 out of thesupports 38. The drum is then more suitable for carrying.

lf preferred, the lower push rod 56 can be made in two parts so that thepart which projects downwardly beyond the frame 22 can be unscrewed fromthe rest of the rod 56 so that the drum will then fit into aconventional drum cover.

The lower end of the casing 12 as shown is uncovered. However, a wiremesh or other decorative cover can be placed over this end provided thatit permits air displacement from within the drum to pass through it.

To assemble the drum, the legs 16 are locked in supports 38 to positionthe skin 28 at a desired height and the foot pedal assembly 18 isattached by inserting screws 20. lf necessary the inclination of thefoot plate 146 can be changed by repositioning screws 140 in theadjustable link 136.

Once assembled, the drum is adjusted for use by tensioning the bolts 34until the lowest required pitch is obtained. As the foot plate 146 isdepressed, the drum will give a range of pitch beginning from the lowestand increasing in frequency to a maximum dictated by the tension in theskin 28. This permits a drummer to strike the skin 28 and by moving thefoot plate 146 he can vary the pitch of the resulting note until thenote dies out, By combining this effect with notes struck with the pedalin any one of a number of different positions it is possible to obtainaffects which are pleasing to the ear and which can be used incombination with other musical instruments to provide novel musicaleffects.

What l claim as my invention is:

1. An adjustable musical drum comprising:

a. a cylindrical casing having a vertical longitudinal axis;

b. a drum head comprising: a circular skin and a hoop attached to theperiphery of the skin and adapted to t relatively closely over thecasing with the skin stretched over an upper end of the casing;

c. a rim adapted to engage the hoop for drawing the hoop over the casingto tension the skin on the said end of the casing;

d. adjustable means coupled to the casing and operable to draw the rimaxially of the casing and towards the other end of the casing to apply apredetermined tension to the skin;

e. a tensioning mechanism operable to move the adjustable means axiallythereby varying the tension in the skin between the predeterminedtension and a higher tension;

f. a foot pedal assembly for coupling to the tensioning mechanism and tothe mounting means for moving the tensioning mechanism to change thetension in the skin continuously between the said predetermined andhigher tensions;

g. the adjustable means comprising: a plurality of the tensioningmechanism comprising:

i. a lower pivot block adapted to reciprocate along said axis inresponse to pedal assembly movements ii. an axial push rod reciprocallycoupled to the casing and having an upper end attached to the lowerpivot block and a lower end coupled to the foot pedal assembly fortransmitting movement from the foot pedal assembly to the lower pivotblock;

iii. a plurality of lower arms extending radially of the lower pivotblock and pivotally connected at their respective outer ends to thecasing;

iv. means connecting the inner ends of the lower arms to the lower pivotblock so that the arms are free to rotate about their outer ends inresponse to axial movements of the lower pivot block; y

v. an upper pivot block adapted to reciprocate along said axis;

vi. a plurality of intermediate arms extending radially outwards anddownwardly from the upper pivot block, each of the intermediate armshaving an inner and connected to the upper pivot block and an outer endpivotally connected to a corresponding lower arm intermediate the endsof the lower arm so that movement of the lower pivot block in one axialdirection is transmitted by the lower and intermediate arms to the upperpivot block to move the upper pivot block in the same direction;

vii. a plurality of upper arms extending radially from the upper pivotblock and having outer ends projecting through the casing;

viii. fulcrum means coupling the upper arms to the casing adjacent outerends of the upper arms for pivotal movement of the upper arms such thata relative large movement of the inner ends of the upper arms results ina relatively small movement of the outer ends; and

ix. means coupling respective inner and outer ends of the upper arms tothe upper pivot block and to the sliders whereby axial reciprocalmovement of the upper pivot block in response to intermediate the endsof the bell-crank lever; a footplate pivotally connected to the outerend of the bellcrank lever so that pressure in the foot-plate results inangular movement of the bell-crank lever; and means coupling the lowerend of the push rod to the bell crank lever for transmitting upwardmovement of the inner end of the bell-crank lever to the push rod.

1. An adjustable musical drum comprising: a. a cylindrical casing havinga vertical longitudinal axis; b. a drum head comprising: a circular skinand a hoop attached to the periphery of the skin and adapted to fitrelatively closely over the casing with the skin stretched over an upperend of the casing; c. a rim adapted to engage the hoop for drawing thehoop over the casing to tension the skin on the said end of the casing;d. adjustable means coupled to the casing and operable to draw the rimaxially of the casing and towards the other end of the casing to apply apredetermined tension to the skin; e. a tensioning mechanism operable tomove the adjustable means axially thereby varying the tension in theskin between the predetermined tension and a higher tension; f. a footpedal assembly for coupling to the tensioning mechanism and to themounting means for moving the tensioning mechanism to change the tensionin the skin continuously between the said predetermined and highertensions; g. the adjustable means comprising: a plurality of axial boltseach of which has a head end engaged against the rim and a threaded end;and a plurality of sliders coupled to the casing for reciprocal axialmovement, each slider having an axially extending opening for threadablyreceiving a corresponding threaded end of a bolt, the sliders beingcoupled to the tensioning mechanism so that the bolts can be tightenedto draw the rim towards the sliders to apply the predetermined tensionto the skin; and h. the tensioning mechanism comprising: i. a lowerpivot block adapted to reciprocate along said axis in response to pedalassembly movements ii. an axial push rod reciprocally coupled to thecasing and having an upper end attached to the lower pivot block and alower end coupled to the foot pedal assembly for transmitting movementfrom the foot pedal assembly to the lower pivot block; iii. a pluralityof lower arms extending radially of the lower pivot block and pivotallyconnected at their respective outer ends to the casing; iv. meansconnecting the inner ends of the lower arms to the lower pivot block sothat the arms are free to rotate about their outer ends in response toaxial movements of the lower pivot block; v. an upper pivot blockadapted to reciprocate along said axis; vi. a plurality of intermediatearms extending radially outwards and downwardly from the upper pivotblock, each of the intermediate arms having an inner and connected tothe upper pivot block and an outer end pivotally connected to acorresponding lower arm intermediate the ends of the lower arm so thatmovement of the lower pivot block in one axial direction is transmittedby the lower and intermediate arms to the upper pivot block to move theupper pivot block in the same direction; vii. a plurality of upper armsextending radially from the upper pivot block and having outer endsprojeCting through the casing; viii. fulcrum means coupling the upperarms to the casing adjacent outer ends of the upper arms for pivotalmovement of the upper arms such that a relative large movement of theinner ends of the upper arms results in a relatively small movement ofthe outer ends; and ix. means coupling respective inner and outer endsof the upper arms to the upper pivot block and to the sliders wherebyaxial reciprocal movement of the upper pivot block in response tomovement at the foot pedal assembly pivots the upper arms in the fulcrummeans resulting in axial movement of the sliders in the oppositedirection to the direction in which the upper and lower pivot blocksmove.
 2. An adjustable musical drum as claimed in claim 1 in which thefoot pedal assembly comprises: a bell crank lever having an inner endand an outer end the bell-crank lever being pivotally attached to thecasing intermediate the ends of the bell-crank lever; a foot-platepivotally connected to the outer end of the bell-crank lever so thatpressure in the foot-plate results in angular movement of the bell-cranklever; and means coupling the lower end of the push rod to the bellcrank lever for transmitting upward movement of the inner end of thebell-crank lever to the push rod.